Environmental Engineering Reference
In-Depth Information
much smaller. You save more money making the equipment smaller than
you pay extra for the fatter pipes, so the whole thing gets cheaper. In other
words, you use big pipes and small pumps instead of small pipes and big
pumps.
The other thing we did was to lay out the pipes first, then the equip-
ment, not the other way around. Normally, people plunk down the equip-
ment to be connected in some arbitrary traditional place, and tell the pipe
fitter to come connect point A to point B. But usually the equipment is in
the wrong place, facing the wrong way, at the wrong height, and there is a
lot of stuff in between, so the pipe has to go through lots of curlicues to get
there, increasing friction by a factor from about 3 to about 6. It makes a lot
more sense to have short straight pipes than long crooked pipes; and, again,
it results in less friction, smaller equipment, less capital cost, and less energy
fighting the friction forever. Also, it is easier to insulate short straight pipes.
So we also saved in this case 70 kilowatts of heat loss with the two-month
payback on thicker insulation.
None of this is rocket science, right? This is just good Victorian engi-
neering, lately forgotten. But it gives you multiple benefits for single expen-
ditures—in that case, less equipment, less capital cost, and less energy cost,
and there are a lot of other benefits, too. It is more reliable, easier to con-
trol, takes up less space, and makes less noise. It turns out, actually, super-
windows like those in our house have ten different benefits, premium
efficiency motors have sixteen, and dimmable electronic ballasts for fluo-
rescent lights have eighteen.Why are we counting just one? When you have
that many benefits to play with, it is not hard to make big savings become
cheaper than small savings, and the savings really add up.You can save one
fourth of the electricity in the country retrofitting lighting systems, another
fourth retrofitting motor systems, and another fourth on everything else.
There's three fourths gone. Not bad, since we spend $200 billion a year on
electricity.
Now let me give a more interesting example of how to apply whole-
system thinking to tunnel through the cost barrier—that is, what we can
do with cars. Ed Colt once accidentally invented a wonderful kind of graph
(figure 4). Apparently he hit the wrong button on the spreadsheet routine
or something and came up with this. I use it here to show the history of
movements of world oil prices over 113 years. It is a very nice way to show
this Brownian random walk, just like any commodity price. All that hap-
pened after 1973 with the first oil shock is that the volatility tripled.
